Pinging.

[Xargon321]

Well my 65 mustang with a 200 80 head and a carter yfa carb. and a duraspark II distributor with msd control box is pinging i have the timing set at 6 btdc and am running 92 octane with no change it only seems to happen after the engine warms up and it is somewhat warm 70+ it will do it more readily if i have been sitting in traffic and get a little warm ( stock gauge reading 1/2 to 3/4 or so) but never gets too hot. it dont seem to do it at anything less then 40 at least i cant hear it if it does. at cruise speed 55-60 i can hold light throttle and it wont do it. push a little more then i will hear it, if i go harder it goes away. at 60+ it will ping consistently but only when warm so far it seems. and if i pulling up a hill it will start pinging about half way up a long hill, short hills are not a problem.

i have chased vacuum leaks and think i have them all solved. i dont think the damper is shifting i have not had a problem keeping a set initial timing. i cant think of what else i might be missing, the distributor vacuum advance is working. at 60 or so Mph rpms are at 2300-2500 so i think i should be at max timing maybe im getting to much is there anything i can do to limit this? its there a easy way to check and see how much timing im getting max? this is my daily driver so i dont need my motor breaking on me

 

[69.5Mav]

Have you changed anthing lately? How do your plugs look.

Ping is normally cause by four interelated things.

Engine running to hot.

A local hot spot on the head or pistons.

Ignition to far advanced.

Mixture to lean.

From your description I would lean toward a local hot spot. You could try some sea foam to clean out a carbon build up hot spot.

I would also check top dead center timing to be sure.

 

[FalconSedanDelivery]

Verify the total timing , initial , plus mechanical , disconnect the vac adv when checking , you probably have too much , total , try it without the vac connected , you can have the dist recurved , its a service I do at my shop

 

[Xargon321]

How do i go about checking total advance? When i set my initial timing it is with the vacuum advance disconnected. Also this morning i was going to work the temp outside was 41-50 and i did not get any pinging at all. Even above 60 mph. I was planning on getting a aluminium rad and electric fan might have to flush the block out the heater core was almost plugged with deposits when i replaced it. And this is my daily driver so if i do have have a recurve done it will probably have to be a new distributor

Plug are auto light 45 one step colder the stock and where just replaced a month ago.

 

[FalconSedanDelivery]

Checking total timing on a Stock Dist can be dangerous , You are in the area of the fan with running parts , I use a Dist Machine ( a Sun Unit ) , but if you have access to a dial back timing light , mark the balancer at TDC 0 , start engine , note on light where you are at to get 0 at idle , then rev engine till it stops advancing ( THE DANGEROUS PART ) note on light where the dial is turned so that when you turn it to get 0 when full advance , it will read on the light , example , you need to rev it to say 4500 , you keep turning the dial till it says 0 down at the balancer , you look on the timing light dial back knob and it says 45 , that is your total , The Falcon Engines from mid 75 and up like lots of initial ( 18-24) but only about 32-34 total , the older like less , with totals around 34-38 , its all in the piston / combustion chamber shape , the late heads that are touted as BEST , do flow best , BUT are Detonation prone , because of a lack of squish , they were designed with EGR to be added , without it they PING , very easily

 

[Xargon321]

well i dont have a timing light that has a dial so i may have to get one but one thing i noticed that is really seems to be heat related if the temp gauge goes over halfway ill get pinging not always a ton but some and if it stays under half i cant hear any even going 60+ down. i might get on the highway and see what it does going 60+ for a period so far i have not been very far with it just back and forth to work. am looking at getting accurate gauge here soon and a timing light with advance dial.

 

[FalconSedanDelivery]

Until then keep your foot out of it , If it Pings that you can hear , its ALSO , ping when you cant , timing by ear is a stop gap measure at best , The biggest KILLER of an otherwise healthy engine is Detonation / Pinging , many engine woes are misdiagnosed as other causes when IT IS the Villain , also like I posted , disconnect the Vac adv , and see if it goes away

 

[JackFish]

From where is the dizzy getting it's vacuum?

 

[Xargon321]

from the bottom port on the carb it dont get vacuum untill you give it some gas then it will move